Electrically-heated instrument.



F. KUHNx ELECTRICALLY HEATED INSTRUMENT.

APPLICATION FILED AUG.30. 1915.

1 %3 1 749:, Patented July 3, 191?,

auuamto'a 3391 M41 F/AV/M FRANK-KUI-IN, F DETROIT, MICHIGAN.

ELECTRICALLY-HEATED INSTRUMENT.

Specification of Letters Patent.

Patented July 3, 1917.

Application filed August 30, 1915. Serial No. 47,928.

To all whom it may concern:

Be it known that I, FRANK KUI-IN, a citizen of the United States of America, residing at Detroit, in the county of \Vayne and State of Michigan, have invented certain new and useful Improvements in Electrically-Heated Instruments, of which the following is a. specification, reference being had therein to the accompanying drawings.

The invention relates to electrically heated instruments, and has for its primary object increase in efficiency in the distribution of the heat from the resistor to the work surface. To this end the invention comprises the novel means for securing better heatconducting contact between adjacent members of the instrument, and further for protesting the surfaces from corrosion as hereinafter set forth.

In the drawing:

Figure 1 is a sectional elevation illustrating an electrically heated soldering iron to which my improvements are applied;

Fig. 2 is a cross section of Fig. 1; and

Fig. 3 is a cross section through the several members of another electrically heated instrument embodying my invention.

In the construction of electrically heated instruments it is usual to employ metals, such as iron, copper. etc., which under the temperature to which the instrument is subjected readily oxidize. As a consequence it is diflicult to maintain good heat conducting contact between adjacent members. for the reason that a film of corrosion will beformed therebetween which acts as a heat insulation. Furthermore, the corrosion of contacting surfaces often causes them to adhere to each other so as to render separation difficult, and this is particularlv objectionable in instruments which are provided with removable tools.

With the present invention these difiieulties have been overcome by rendering the contacting surfaces of adjacent members non-corrodible. As shown in Fig. 1, A is an electric heater having heat-distributing body l% which is recessed for receiving the removable tool (I. such as a soldering iron. The body B may be formed of any suitable material such as cast iron, and the electric heat is imparted thereto from a suitable resistor I) wound therearound and insulated therefrom. The member C is also formed of any suitable material, such as copper, and the parts are machined to form a close fit so as to secure good heat-conducting contact.

To avoid corrosion and the ditficulties resulting therefrom. the members B and C are treated by any suitable process for rendering the contacting surfaces thereof non-corrodible, such surfaces being indicated by heavy lines. Preferably this treatment is one which coats the surface with a non-corrodible metal, such as aluminum, Without impairing its heat conduction. Thus the heat which is developed in the resistor D and is transmitted therefrom to the member B is readily transferred to the member G through the contacting surfaces. Also this is accomplished without any corrosion of the surfaces so that any time these members may be separated.

In Fig. 3 is shown a modified construction in whichE is an armored electrical heating unit, and F and G members for contacting the opposite sides of said unit. The contacting surfaces of all of these members are treated to be rendered non-corrodible, and therefore when they are clamped together the heat conduction is more perfect.

What I claim as my invention is In an electrically heated instrument, adjacent members in heat-conducting contact, the contacting surfaces of said members being coated with aluminum.

In testimony whereof I affix my signa ture in presence of two witnesses.

FRANK KUHN.

Witnesses:

CHAS. H. REUTnLsTnRz, ROLAND DRESSEL. 

